Conduct a Phase I clinical trial of dose ranging 28 day repeat dose to test wheter Dimethandrolone undecanoate will be well tolerated and will supress gonadotropins to supress spermatogenesis. The objective ofthe trial is to determine, in a Phase I clinical trial in men , whether oral doses of a new chemical contraceptive, Dimethandrolone undecanoate, will be well tolerated and if repeated dosing over 28 days will be effective in suppressing gonadotropins. Results from the Phase I trial will establish ifthe agents could be evaluated in a longer-term sperm suppression clinical trial, pursuant to obtaining FDA approval as a contraceptive. Therefore, the objective of this Task Order is to conduct the study so that the overall objectives of the Phase I clinical trial are successfully achieved.